Removal of Chromium From Contaminated Water

1999 ◽  
Author(s):  
Shariar Jahanian ◽  
Hossein Rostami
Keyword(s):  
Fly Ash ◽  
Petroleum Products ◽  
Contaminated Water ◽  
Column Test ◽  
Superfund Sites ◽  
Barrier Material ◽  
Reactive Barrier ◽  
The Past ◽  
New Material ◽  
Different Sources

Abstract Over the past 15 years, about one half million sites with potential contamination have been reported to federal or state authorities. Of these, about 217,000 sites still need remediation (1) and new contaminated sites continue to appear each year. The most common type of contaminants are metals, solvents and petroleum products. Heavy metals are present in two thirds of DOD and superfund sites and about 50% of DOE and RCRA sites. AAM is a new material that possesses the ability to remove heavy metal from conaminated water. AAM consists of fly ash activating chemicals and fillers. AAM barrier material was used to remove Cr from contamination water. Fly ash from three different sources were used to produce reactive barrier of different permeability. AAM materials with permeability 10−2 to 10−1 was created. Only highest permeability proved to be viable for reactive barrier material. AAM barrier from three ash sources with permeability of 10−1 was produced and crushed into pelletized form. To determine effectiveness of the various barriers batch test was performed, based on that result the column test was conducted. In this work contamination barrier with controled permeabilty was tested to determine its ability to remove Cr from contaminated water. AAM barrier material was used in column test to remove Cr from 1000 ppm and 10 ppm solution. The results show that AAM barrier is very effective in removing Cr from highly contaminated water (up 99% efficiency).

Removal of Cadmium From Contaminated Water

1999 ◽  
Author(s):  
Shariar Jahanian ◽  
Hossein Rostami
Keyword(s):  
Fly Ash ◽  
Petroleum Products ◽  
Contaminated Water ◽  
Column Test ◽  
Superfund Sites ◽  
Barrier Material ◽  
Reactive Barrier ◽  
The Past ◽  
New Material ◽  
Different Sources

Abstract Over the past 15 years, about one half million sites with potential contamination have been reported to federal or state authorities. Of these, about 217,000 sites still need remediation (1) and new contaminated sites continue to appear each year. The most common type of contaminants are metals, solvents and petroleum products. Heavy metals are present in two thirds of DOD and superfund sites and about 50% of DOE and RCRA sites. AAM is a new material that possesses the ability to remove heavy metal from conaminated water. AAM consists of fly ash activating chemicals and fillers. AAM barrier material was used to remove Cd from contamination water. Fly ash from three different sources were used to produce reactive barrier of different permeability. AAM materials with permeability 10−2 to 10−1 was created. Only highest permeability proved to be viable for reactive barrier material. AAM barrier from three ash sources with permeability of 10−1 was produced and crushed into pelletized form. To determine effectiveness of the various barriers batch test was performed, based on that result the column test was conducted. In this work contamination barrier with controled permeabilty was tested to determine its ability to remove Cd from contaminated water. AAM barrier material was used in column test to remove Cd from 1000 ppm and 10 ppm solution. The results show that AAM barrier is very effective in removing Cd from highly contaminated water (up 99% efficiency).

The Effect of Dry Mix Sodium Hydroxide onto Workability and Compressive Strength of Geopolymer Paste

2020 ◽  
Vol 12 (9) ◽  
Author(s):  
A. Z. Mohd Ali ◽  
◽  
N. A. Jalaluddin ◽  
N. Zulkiflee ◽  
◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Alkaline Solution ◽  
High Emission ◽  
New Material ◽  
Curing Regime ◽  
Solid Form ◽  
Geopolymer Paste

The production of ordinary Portland cement (OPC) consumes considerable amount of natural resources, energy and at the same time contribute in high emission of CO2 to the atmosphere. A new material replacing cement as binder called geopolymer is alkali-activated concrete which are made from fly ash, sodium silicate and sodium hydroxide (NaOH). The alkaline solution mixed with fly ash producing alternative binder to OPC binder in concrete named geopolymer paste. In the process, NaOH was fully dissolved in water and cooled to room temperature. This study aims to eliminate this process by using NaOH in solid form together with fly ash before sodium silicate liquid and water poured into the mixture. The amount of NaOH solids were based on 10M concentration. The workability test is in accordance to ASTM C230. Fifty cubic mm of the geopolymer paste were prepared which consists of fly ash to alkaline solution ratio of 1: 0.5 and the curing regime of 80℃ for 24 hours with 100% humidity were implemented. From laboratory test, the workability of dry method geopolymer paste were decreased. The compressive strength of the dry mix of NaOH showed 55% and the workability has dropped to 58.4%, it showed strength reduction compared to the wet mix method.

scholarly journals Ceramic hydroxyapatite foam as a new material for Bisphenol A removal from contaminated water

2021 ◽  
Author(s):  
Hamza Khallok ◽  
Mohamed Zbair ◽  
Satu Ojala ◽  
Kaisu Ainassaari ◽  
Rachid Brahmi ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Contaminated Water ◽  
New Material ◽  
Ceramic Hydroxyapatite

Neoteric Material Based on Renewable Resources for Metal-Contaminated Waters

2021 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Iolanda-Veronica Ganea ◽  
Alexandrina Nan ◽  
Iulia Neamțiu ◽  
Călin Baciu
Keyword(s):  
Electron Microscopy ◽  
Renewable Resources ◽  
Absorption Spectrometry ◽  
Contaminated Water ◽  
Metal Release ◽  
Continuous Increase ◽  
X Ray ◽  
Environmental Media ◽  
New Material ◽  
Low Costs

A continuous increase of environmental pollution has been recorded worldwide, during recent decades, as a result of industrialization and urbanization. In particular, metal release in the environmental media may threaten human health, due to their persistence and accumulation in the food chain. We report here the functionalization of chitosan with poly(benzofurane-co-arylacetic) acid, which is a new material with the ability of complex metals from contaminated water. The synthesized polymer was structurally investigated by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray photon electron microscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR), while heavy metals were determined by atomic absorption spectrometry. Different isotherms and kinetic models were used to describe the absorption equilibrium and the behavior of the material, based on the initial pollutant concentration and contact time. The results are pointing out that such natural materials can be easily synthesized, at low costs, thus offering attractive solutions for wastewater treatment.

Introductory remarks

1977 ◽  
Vol 280 (972) ◽  
pp. 105-105
Keyword(s):  
Climatic Change ◽  
Food Supply ◽  
Time Scale ◽  
Food Production ◽  
Rapid Change ◽  
Climatic Fluctuations ◽  
The Past ◽  
Wide Range ◽  
The Subject ◽  
Different Sources

In the last year or two there has been a remarkable increase in the interest, both popular and scientific, in the subject of climatic change. This stems from a recognition that even a highly technological society is vulnerable to the effects of climatic fluctuations and indeed may become more so, as margins of surplus food production are reduced, and nations become more interdependent for their food supply. In this respect our concern is with quite small changes - a degree (Celsius) or less in temperature and 10 % or so in rainfall. Probably we may discount some of the more alarmist suggestions of an imminent and rapid change towards near glacial conditions as these are based on very sketchy evidence. However, whatever the time-scale of climatic fluctuations with which we are concerned, we may hope to learn a great deal which is relevant to the factors which will control our future climate from the study of its more extreme vagaries in the past. Information relevant to the weather in such extreme periods is coming forward in increasing detail and volume from a wide range of disciplines. The variety of the evidence, its lack of precision as a strict measure of climate, and the number of different sources all make it difficult for an individual to build up a clear picture of past climates. However such a picture is needed, if explanations and interpretation are to be possible. Ideally one would need a synchronous picture of the climate of the whole world at selected epochs in the past. Various international programmes are directed to forming such pictures.

scholarly journals Effect of tannic acid on urease and protease produced from Proteus mirabilis

2019 ◽  
Vol 13 (1) ◽  
pp. 82-86
Author(s):  
Omar S. Al-Zaidi ◽  
Luma abd alhady Zwein
Keyword(s):  
Tannic Acid ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Protease Production ◽  
Contaminated Water ◽  
Negative Bacterium ◽  
Urine Ph ◽  
Back Ground ◽  
Vitek 2 ◽  
Different Sources

Back ground: P.mirabilis is a gram negative bacterium, motile with its peritrichous flagella .Widely distributed in environment, especially in contaminated water and soil, Many virulence factors like LPS, urease, protease, hemolysin and biofilm formation play an important roles in the pathogenicity of P. mirabilis. Urease is a Nickel containing enzyme causes elevation of urine pH after hydrolyzing urea to ammonia and CO2 forming stones that blocks the urinary track. Aims: The effect of tannic acid on the production of urease and protease.                                                                        Material and methods: Twenty one isolates of Proteus were collected from different sources, Clinical and animal sources all isolates were cultured on MacConkey and blood agar and identification of P. mirabilis by, Vitek -2 compact system. Determine the effect of tannic acid on the production of urease and protease.                                                                                              Results: Twenty one isolates of Proteus were identified depending on Vitek-2 compact system, after identification, it turns out that only 18  isolate were P. mirabilis. All isolates were 100% able to produce urease and 72.2%  isolate were able to produce protease. The addition of tannic acid showed an inhibitory effect on urease and protease production. Conclusion: The effect of tannic acid on urease and protease depending on concentration, type of strain, incubation period, number of isolates and truculence of isolate.  

Introduction: Current perspectives on positive polarity

Linguistics ◽  
2018 ◽  
Vol 56 (2) ◽  
pp. 283-300
Author(s):  
Mingya Liu ◽  
Gianina Iordăchioaia
Keyword(s):  
Internal Structure ◽  
Negative Polarity ◽  
Positive Polarity ◽  
Negative Polarity Items ◽  
Theoretical Concepts ◽  
Polarity Items ◽  
The Past ◽  
Linguistic Research ◽  
Semantics And Pragmatics ◽  
Different Sources

Abstract Polarity sensitivity has been an established key topic of linguistic research for more than half a century. The study of polarity phenomena can be extremely revealing about the internal structure of a language, as they usually involve an interaction at the interface between syntax, semantics and pragmatics. In the past, most attention was paid to negative polarity items. However, recent years have witnessed a growing interest in positive polarity items. As a continuation of this trend, this issue collects four papers dedicated to positive polarity items, which enrich the empirical domain with novel observations from different languages and appeal to diverse theoretical concepts such as scalarity and presupposition in their modeling of positive polarity. The results show that positive polarity is a distributional phenomenon that has different sources and most likely cannot be modeled in a unifying way, although there may be subsets of positive polarity items that allow unifying accounts.

scholarly journals Human fascioliasis infection sources, their diversity, incidence factors, analytical methods and prevention measures

Parasitology ◽  
2018 ◽  
Vol 145 (13) ◽  
pp. 1665-1699 ◽  
Author(s):  
S. Mas-Coma ◽  
M. D. Bargues ◽  
M. A. Valero
Keyword(s):  
Preventive Measures ◽  
Wild Plants ◽  
Cultivated Plants ◽  
Contaminated Water ◽  
Prevention Measures ◽  
The Past ◽  
Urban Markets ◽  
Human Fascioliasis ◽  
Questionnaire Surveys ◽  
First Time

AbstractHuman fascioliasis infection sources are analysed for the first time in front of the new worldwide scenario of this disease. These infection sources include foods, water and combinations of both. Ingestion of freshwater wild plants is the main source, with watercress and secondarily other vegetables involved. The problem of vegetables sold in uncontrolled urban markets is discussed. Distinction between infection sources by freshwater cultivated plants, terrestrial wild plants, and terrestrial cultivated plants is made. The risks by traditional local dishes made from sylvatic plants and raw liver ingestion are considered. Drinking of contaminated water, beverages and juices, ingestion of dishes and soups and washing of vegetables, fruits, tubercles and kitchen utensils with contaminated water are increasingly involved. Three methods to assess infection sources are noted: detection of metacercariae attached to plants or floating in freshwater, anamnesis in individual patients, and questionnaire surveys in endemic areas. The infectivity of metacercariae is reviewed both under field conditions and experimentally under the effects of physicochemical agents. Individual and general preventive measures appear to be more complicated than those considered in the past. The high diversity of infection sources and their heterogeneity in different countries underlie the large epidemiological heterogeneity of human fascioliasis throughout.

scholarly journals Caenagnathids of the Dinosaur Park Formation (Campanian) of Alberta, Canada: anatomy, osteohistology, taxonomy, and evolution

2020 ◽  
Vol 8 ◽  
pp. 105-153 ◽  
Author(s):  
Gregory Funston
Keyword(s):  
Body Size ◽  
Skeletal Maturity ◽  
Niche Overlap ◽  
Niche Space ◽  
The Past ◽  
Adult Body ◽  
New Material ◽  
Taxonomic Framework ◽  
Dinosaur Park Formation ◽  
Insight Into

Our understanding of caenagnathid anatomy, diversity, and ecology has improved considerably in the past twenty years, but numerous issues still remain. Among these, the diversity and taxonomy of caenagnathids from the Dinosaur Park Formation of Alberta, Canada, have remained problematic. Whereas some authors recognize three genera, others suggest only two were present, and there is considerable disagreement about which specimens are referable to which genus. This study aims to resolve this issue by reviewing the known specimens and using osteohistology, to establish a testable taxonomic framework of Dinosaur Park Formation caenagnathids. Numerous new specimens from all regions of the skeleton provide insight into morphological variation in caenagnathids, and three morphotypes are recognized based on a combination of morphological features and body size. Osteohistology shows that representatives in each body size class are at skeletal maturity, and therefore supports the delineation of three taxa: the smaller Citipes elegans gen. nov., the intermediate Chirostenotes pergracilis, and the larger Caenagnathus collinsi, new material of which shows it rivalled Anzu wyliei in size. However, these analyses also raise concerns about the referral of isolated material to each taxon in the absence of skeletal overlap between specimens or osteohistological analysis. Caenagnathids are consistently recovered throughout the Dinosaur Park Formation interval, and two geographic clusters of increased abundance probably reflect collection and taphonomic biases. The coexistence of three taxa was apparently facilitated by differences in both adult body size and functional morphology of the dentary and pes, which suggests that caenagnathids minimized niche overlap rather than subdividing niche space. Regardless, little is known of the exact roles caenagnathids played in Late Cretaceous ecosystems. Incorporation of the new material and taxonomic framework into a phylogenetic analysis drastically improves our understanding of the relationships between caenagnathines, and sheds light on the evolution of body size in caenagnathids and its role in their diversification.

scholarly journals Determination of chemical species in fly ash collected at different sources

1994 ◽  
Vol 6 (4) ◽  
pp. 113-118
Author(s):  
Ildikó Bódog ◽  
Klára Polyák ◽  
József Hlavay
Keyword(s):  
Fly Ash ◽  
Chemical Species ◽  
Different Sources
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